/Engine/Source/Runtime/Slate/Public/Widgets/Layout/SScrollBarTrack.h
Arrange 3 widgets: the top track, bottom track, and thumb.
class SScrollBarTrack : public [SPanel](API\Runtime\SlateCore\Widgets\SPanel)
bool
bIsAlwaysVisible
TPanelChildren<...
Children
float
MinThumbSize
float
OffsetFraction
EOrientation
Orientation
float
ThumbSizeFraction